Utilizing the waste heat much generated by vehicles and others is now under investigation. A regenerator system for vehicles that utilizes the waste heat generated by vehicles is described, for example, in JP-A 1-267346. According to this, the waste heat from an engine in the vehicle that is running is applied to a hydrogen occlusion alloy to thereby make the alloy release hydrogen gas, the thus-released hydrogen gas is absorbed by the alloy at the time of engine start, and the reaction heat thus generated by the alloy is supplied to the devices to be warmed up to thereby promote the engine warming up in a vehicle to be driven. In the regenerator system for vehicles, the waste heat is effectively accumulated and is efficiently utilized, but is not utilized in a cooler (air conditioner) that is a typical heat utilization system in vehicles. In this, therefore, the waste heat is not always effectively utilized.
On the other hand, an adsorption-type regenerator apparatus that utilizes the heat adsorbed by an adsorbent is known for heat utilization in cooling systems. The regenerator system equipped with such an adsorption-type regenerator apparatus is installed in buildings, houses, vehicles and others, in which the waste heat or hot heat generated by it is utilized for effective recycling of energy resources. In the regenerator system of the type, a desorption process of heating the adsorbent so as to desorb the adsorbate such as water from it and an adsorption process of cooling the adsorbent from which the adsorbate has been desorbed to thereby make the adsorbent again adsorb the adsorbate are repeated to drive the system. For efficient repetition of the desorption process and the adsorption process in the system, the adsorbent that adsorbs and desorbs an adsorbate must have adequate adsorption characteristics that correspond to the heat source to be applied to the system.
In general, the heat obtainable from cooling water or solar heat in cogeneration units, fuel cells, car engines and others is relatively at low temperature of at most 120° C., mostly at most 105° C., more mostly at around 60 to 100° C. or so. Accordingly, it is desired to develop an adsorbent capable of realizing efficient adsorption and desorption of adsorbate even for such low-temperature waste heat.
Above all, practical use of compact regenerator systems equipped with such an adsorbent is earnestly desired for automobiles that generate much waste heat and therefore have a problem in that the fuel efficiency is further lowered by the use of air conditioners therein, as so mentioned hereinabove.